U.S. Pat. No. 7,413,532, which is incorporated herein by reference, discloses an exercise apparatus having a weight stack for opposing a given exercise motion. The weight stack has a first set of a plurality of primary weights vertically stacked on each other, a primary weight selector having a plurality of settings selectively controlling the number of weights to be lifted during the exercise motion, a second set of a plurality of secondary weights, and a secondary weight selector having a plurality of settings selectively controlling the number of secondary weights to be lifted during the exercise motion, the secondary weights providing supplemental incremental weight.